Maintain experimental human and animal tumors in a frozen state for the Division of Cancer Treatment Cancer Research Program and for use by the international research community. This bank is considered to be a unique resource as many of the tumors are not otherwise available. Tumors from this bank will be shipped to investigators whom the Government finds to be qualified, who demonstrate a need for a particular tumor, and who are able to propagate that tumor in their laboratories for experimental purposes. At present, the tumor bank contains approximately 343 mouse, 53 rats, and 23 other tumor lines.